Spring assembly



Jan. 25, 1966 DUNCAN 3,230,558

SPRING ASSEMBLYv Filed June 28, 1963 6 0 0 0 O C g 4 Q 0 4') 4 "o n 0 0 0 e 4% KT NEYS United States Patent 3,230,558 SPRING ASSEMBLY Sheldon F. Duncan, Scarsdale, N.Y., assignor to Simmons Company, New York, N .Y., a corporation of Delaware Filed June 28, 1963, Ser. No. 291,443 3 Claims. (Cl. -353) The invention relates to spring assemblies and more particularly to mattress cores of the general type disclosed in United States Patent No. 1,677,233 to John F. Gail.

The mattress construction disclosed in the Gail patent has a core composed of a series of nested rows of integrally connected, closed textile fabric pockets, each pocket containing a double-ended, coil wire, axially vertical spring. The springs may be cylindrical, i.e., the exterior diameter of the turns of the coil wire spring being the same from the top to the bottom of the spring, or preferably, the springs may have a barrel shape wherein the diameter of the turns of the springs in the pockets is greater in an intermediate zone of the coil wire spring than at the ends thereof.

In the manufacture of mattress cores of this type, it is general practice first to make up strips of spring-filled pockets, or a continuous length of said pockets, and then to arrange a series of these strips or the continuous length in a series of parallel, nested rows, sufficient in number and of proper length to form a mattress core having the dimensions desired. The rows are transversely tied in this arrangement, to interconnect adjacent rows and produce an integral mattress core.

The entire operation can be carried out by hand or can be more efficiently carried out by the methods described in United States Patent No. 2,805,429 to Woller, which is assigned to the assignee of this patent application. This patent describes a very effective method which thrusts long needles transversely through an assembly of nested, parallel rows of pocketed springs and utilizes these needles to draw lines of twine through the core. The needles are arranged in pairs, each pair of needles being used to draw the ends of a single twine connector through the assembly. After being pulled through the spring assembly, the ends of the twine connectors are removed f-rom the pairs of needles and are manually tied together to form loops of twine that unite the parallel rows of springs in an integral formation.

Although mattress cores having excellent body support characteristics are produced by this method, a noticeable dimensional variation tends to result from the manual tying operation, not only from operator to operator, but also in the work of a given operator in a given work period. This condition, if not carefully policed, can cause undesirable appearance characteristics.

It is an object of the present invention to provide an improved mattress core of the general type described. It is a further object to provide a mattress core which is uniform in dimension. It is another object to provide a mattress core in which the rows of springs therein are uniformly interconnected throughout the entire area of the mattress. These and other objects of the invention are more particularly set forth in the following detailed description and in the accompanying drawings of which:

FIGURE 1 is a fragmentary perspective view of a mattress core made in accordance with the invention;

FIGURE 2 is an enlarged plan view of the mattress core shown in FIGURE 1;

FIGURE 3 is an enlarged sectional view taken along line 33 of FIGURE 2;

FIGURE 4 is an enlarged sectional view taken along line 4-4 of FIGURE 2; and

FIGURE 5 is an enlarged perspective view of a connector.

Generally, the invention provides an improved mattress core of the type described wherein the rows of springs are uniformly interconnected by a series of trans versely extending, spaced connectors of equal predetermined lengths, having anchoring heads at each end. The connectors are positioned approximately midway between the top and bottom faces of the core and thereby hold the intermediate portions of adjacent rows in touching contact with one another. In the completed mattress core, the connectors are substantially equally tensioned and hold the rows of springs in a slightly laterally-compressed condition. Thus, there is provided a mattress core which is of constant width throughout its entire length and in which the individual coil springs support each other uniformly, in upstanding condition, throughout the entire area of the mattress core.

A mattress core 11 having these improved characteristics is illustrated in FIGURE 1. The mattress core 11 comprises a long strip 13 of pocketed springs that has been arranged in serpentine fashion to produce a series of thirteen nested, parallel rows of springs. Usually, it is more convenient to provide a strip of sufficient length to make a complete core assembly of the desired area rather than use a plurality of shorter strips. The parallel rows of springs are transversely interconnected by connectors 15 having anchoring heads 17 at each end to form an integral mattress core construction.

The strip 13 of pocketed springs is produced by d-oubling an elongated panel of textile fabric and sewing the doubled fabric at equally spaced points along its length to provide a series of parallel lines of stitching 19 (FIG. 4 that define pockets 21 therebetween which are disposed transverse the length of the strip. A doubleended wire coil spring 23 is inserted into each of the pockets 21 so that the axes of the springs 23 are generally parallel. The springs 23 may have any suitable shape, preferably however, they are somewhat barrel-shaped. The open ends of the pockets 21 are then closed by sewing along the margins of the fabric to provide a longitudinal line of stitching 25.

The connectors 15 are preferably made of twine; however, other suitable materials in string-like form may also be used. The connectors 15 are of predetermined, equal lengths, proportioned so that they will be in tension in the completed core to hold the rows of springs tightly together.

The anchoring heads 17 may be fashioned with any shape that will remain outside the outer surfaces of the fabric against which they will bear, in the completed mattress core. The heads 17 may comprise detachable buttons or the like which may be attached to the end of a connector 15 after it has been inserted through the spring assembly. Preferably, the heads 17 comprise flat metal cross head elements which are pre-crimped to the end of the string connectors 15 in T-like fashion, as shown in FIGURE 5. Heads of this type can be economically provided and are susceptible of being easily drawn through the spring assembly and then pivoted or turned into anchoring position.

As shown in FIGURES 1 and 2, the preferred connector 15 has a length approximately equal to twice the width of the finished mattress core and is accordingly disposed in the core in a half-loop configuration. However, connectors approximately equal in length to the width of the core may also be used which likewise have anchoring heads at each end. Of course, twice as many connectors of this type are necessary.

Because the connectors 15 serve not only to intercon nect the rows of springs into an integral construction that can be handled throughout the remaining steps of the mattress-forming operation, but also retaining the individual springs in assembled Working arrangement throughout the life of the completed mattress, it is important that theconnectors provide interconnections that are uniform throughout the entire mattress.

When the interconnections are made by manually tying twine connectors into loops, inherently, as in any manual operation, some variations occur in the tightness with which the connectors are tied. These variations, unless carefully controlled so as to be held to a minimum, can give rise to small but unsightly disruptions of the side lines of the mattress in certain areas.

It has been found that by using the connectors 15 which have anchoring heads at each end and are of the same predetermined length, the finished mattress core has a width that is independent of the variations inherent in the human operator. Accordingly, each core is uniform throughout its length, and cores produced at dilferent times, on different machines and by different operators are of uniform construction.

Because all the connectors 15 are of equal, predetermined lengths, the rows of individual pocketed springs are held in nested touching arrangement by substantially the same force throughout the entire length of the mattress core. It is important that adjacent springs are interconnected by the proper amount of force to produce the desired mutual support to maintain the individual springs upright. The interconnection should not be too loose or the mattress core will not provide satisfactory body support. However, the interconnection also should not be too tight lest the springs lose their features of individuality. By using the connections 15, the desired amount of interconnecting force can be accurately obtained. Accordingly, the finished core has uniform resilience characteristics at all points across its entire area, as well as trim, straight peripheral lines.

One method of forming the improved mattress core is more particularly described in copending US. application Serial No. 291,350, filed the same date as this application, of which Walter Stumpf is the inventor. In this method, an assembly of nested rows of pocketed springs is first impaled on an array of pairs of elongated needles. The anchoring heads 17 of the connectors 15 are inserted into chambers provided in the tips of the needles wherein they are drawn through the spring assembly as the needles are withdrawn therefrom. During the withdrawal of the needles, the spring assembly is simultaneously compressed so that the connector heads 17 travel completely out of the spring assembly, whereat they can be easily detached from the needles. The mattress core is then released from compression so that its inherent resiliency causes it to expand to the shape allowed by the connectors 15.

The invention provides an improved mattress core which can be manufactured more economically and in which the structural uniformity is achieved without the careful control which heretofore attended the manual tying of connectors into loops.

Various of the features of the invention are set forth in the following claims:

What is claimed is:

1. A mattress core which includes a series of nested rows of integrally connected closed textile fabric pockets, each pocket containing a double-ended, axially-vertical, wire coil spring, and a series of spaced connectors extending transversely through the series of rows between the top and bottom faces of t e core holding the intermediate parts of adjacent touching rows in contact with one another, said connectors having a head at each end and being of predetermined length so that substantially similar force is exerted by each of said connectors in holding said rows together.

2. A mattress core which includes a series of nested rows of integrally connected closed textile fabric pockets, each pocket containing an axially vertical wire coil spring, the end turns of which springs are located in spaced planes constituting the top and bottom faces of the core, and a series of tensioned connectors each comprising a pair of spaced strands extending transversely through the rows intermediate the top and bottom faces of the core holding adjacent touching rows in contact with one another, each said pair of strands comprising a half loop of predetermined length having at each end a head connected thereto so that the tension in each of said series of installed connectors is substantially equal.

3. A mattress core which includes a series of nested rows of integrally connected closed textile fabric pockets, each pocket containing a double-ended, axially-vertical, wire coil spring, and a series of spaced substantially inextensible connectors extending transversely through the series of rows between the top and bottom faces of the core holding the intermediate parts of adjacent touching rows in contact with one another, each of said connectors having a metal head crimped at each end in T-like fashion and each of said connectors being of predetermined equal length so that substantially similar force is exerted by each of said connectors in holding said rows together.

References Cited by the Examiner UNITED STATES PATENTS 2,098,140 11/1937 Fridolph 5-356 2,805,429 9/ 1957 Woller 5-353 3,080,578 3/1963 Novascone 5-353 3,146,517 9/1964 Skeen 2991.4 3,168,792 2/1965 Stumpf 5-353 XR FRANK B. SHERRY, Primary Examiner. 

1. A MATTRESS CORE WHICH INCLUDES A SERIES OF NESTED ROWS OF INTEGRALLY CONNECTED CLOSED TEXTILE FABRIC POCKETS, EACH POCKET CONTAINING A DOUBLE-ENDED, AXIALLY-VERTICAL, WIRE COIL SPRING, AND A SERIES OF SPACED CONNECTORS EXTENDING TRANSVERSELY THROUGH THE SERIES OF ROWS BETWEEN THE TOP AND BOTTOM FACES OF THE CORE HOLDING THE INTERMEDIATE PARTS OF ADJACENT TOUCHING ROWS IN CONTACT WITH ONE ANOTHER, SAID CONNECTORS HAVING A HEAD AT EACH END AND BEING OF PREDETERMINED LENGTH SO THAT SUBSTANTIALLY SIMILAR FORCE IS EXERTED BY EACH OF SAID CONNECTORS IN HOLDING SAID ROWS TOGETHER. 